She told the station's five million listeners: "The M25 motorway is due to close for one whole week in August as the Department of Health and sports officials are organising a fitness event which is being billed as the ultimate endurance race.

"So that's to close the M25 motorway for one whole week in August and that will take place the 1st to the 8th of August 2016.

"Teams of four people are invited to walk, jog or run to complete the 117 miles that make up the second longest orbital motorway in the world.

Katie on her radio show (Image: LBC)

"Well I'm up for that if only to go and mock people that are causing such chaos and havoc.

"I wonder if that's going to go down very well, shutting the M25 motorway."

Former Apprentice contestant Hopkins was taken in by a satirical story which was posted online in April.

It read: "The Orbital Committal, a race intended for only those crazy enough to have a go, is due to take place from 1-8 August 2016, and teams of four people are being invited to walk, jog or run the complete 117 miles that make up the second-longest orbital motorway in the world.

"Although it is hoped that most teams will be able to complete the course within seven days, those who go beyond this time will be allowed to continue on the hard shoulder."

Hopkins spoke about the fictional event after complaining that road closures for Ride London had left her struggling to reach work.

The 41-year-old realised her blunder before the end of her show on Saturday.

She added: "Just to clarify the M25 will not be closed. I'm quite sad actually because I was quite looking forward to going.

"But just to verify that won't be happening next week. I would also say there have been much bigger spoofs that I have probably been caught out on."

Katie told her listeners the busy motorway would be closed for a whole week (Image: Grant Falvey/LNP/REX/Shutterstock)

The M25 closure story appeared on satirical website Southend News Network this spring.